Anxiety disorders are a group of psychological conditions whose key features include excessive anxiety, fear, worry, avoidance, and compulsive rituals, and produce or result in inordinate morbidity, overutilization of healthcare services, and functional impairment. These disorders are among the most prevalent psychiatric conditions in the United States; women are more likely than men to experience anxiety disorders. Anxiety disorders listed in the Diagnostic and Statistical Manual of Mental Disorders (4th Ed., The American Psychiatric Association, Washington, D.C., U.S.A., 1994, pp. 393 to 444), include panic disorder with and without agoraphobia, agoraphobia without history of panic disorder, specific phobia, social phobia, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), acute stress disorder, generalized anxiety disorder (GAD), anxiety disorder due to a general medical condition, substance-induced anxiety disorder, and specific phobias.
Panic disorder is an anxiety disorder whose essential feature is the presence of recurrent panic attacks that are discrete periods of intense fear or discomfort. The attacks usually last minutes (or, rarely, hours), are unexpected and do not, as in simple phobia, tend to occur immediately before or on exposure to a situation that almost always causes anxiety. Panic attacks typically begin with the sudden onset of intense apprehension or fear, and are accompanied by physical symptoms such as shortness of breath, dizziness, faintness, choking, palpitations, trembling, sweating, shaking, nausea, numbness, hot flushes or chills, chest pain or the like. Panic disorder may be associated with agoraphobia, in severe cases of which the person concerned is virtually housebound.
In obsessive-compulsive disorder, the primary symptom is recurrent obsessions (i.e., recurrent and intrusive thoughts, images or urges that cause marked anxiety) and/or compulsions (i.e., repetitive behaviors or mental acts that are performed to reduce the anxiety generated by one's obsessions) of sufficient severity to cause distress, be time consuming or to interfere significantly with a person's normal routine or lifestyle. Anxiety is an associated feature of this disorder: an affected person may, for example, show a phobic avoidance of situations that involve the cause of the obsession. Typical obsessions concern contamination, doubting (including self-doubt) and disturbing sexual or religious thoughts. Typical compulsions include washing, checking, ordering, and counting.
Social anxiety disorder is characterized by the persistent fear of social or performance situations in which embarrassment may occur, such as parties, meetings, eating in front of others, writing in front of others, public speaking, conversations, meeting new people, and other related situations. Exposure to social or performance situations provokes an immediate anxiety response, as well as sweating, trembling, racing or pounding heartbeat, mental confusion, and a desire to flee. Social avoidance and isolation can also become extreme, especially in the more generalized condition.
There is a need for new treatment agents to alleviate the symptoms of social anxiety disorder, obsessive compulsive disorder or a panic disorder, in order to allow subjects with these conditions to live more productive and enjoyable lives.